Standard deviation, or filter noise, of the matched filter output (Eq. (16)) versus filter scale θ₅₀₀ = c₅₀₀θ_m for the different experimental setups, as labeled. The red curves give results for the Planck satellite and two future missions proposed to ESA, COrE and PRISM. The first has similar angular resolution to Planck (~ 5 arcmin FWHM), but lower noise, while PRISM has both lower noise and higher resolution at ~ 2.6  arcmin. The blue curves show the noise levels for SPT/ACT, SPT-Pol and SPT-3G/ACT-Pol. All curves assume the filter is perfectly matched to the clusters. The experimental characteristics are summarized in Table 1.